Wikipedia:Reference desk/Computing

The Wikipedia Reference Desk covering the topic of computing.
Computing #eee #f5f5f5 #eee #aaa #aaa #aaa #00f #36b #000 #00f computing Wikipedia:Reference desk/Computing Computing WP:RD/C

Welcome to the computing reference desk. Want a faster answer? Main page: Help searching Wikipedia How can I get my question answered? Provide a short header that gives the general topic of the question. Type '~~~~' (that is, four tilde characters) at the end – this signs and dates your contribution so we know who wrote what and when. Post your question to only one desk. Don't post personal contact information – it will be removed. All answers will be provided here. Specific questions, that are likely to produce reliable sources, will tend to get clearer answers, Note: We don't answer (and may remove) questions that require medical diagnosis or legal advice. We don't answer requests for opinions, predictions or debate. We don't do your homework for you, though we’ll help you past the stuck point. We are not a substitute for actually doing any original research required, or as a free source of ideas. Ready? Ask a new question! How do I answer a question? Main page: Wikipedia:Reference desk/Guidelines The best answers address the question directly, and back up facts with wikilinks and links to sources. Do not edit others' comments and do not give any medical or legal advice.

skip to bottom   Choose a topic: Computing desk Entertainment desk Humanities desk Language desk Mathematics desk Science desk Miscellaneous desk Archives   See also: Help desk Village pump Help manual

December 27

Help Translating Phone Specs Into Quality Of Experience For VR

So, for something to do over the winter months, I decided I wanted to buy either an S8, S8+, or Note 8 and a Gear Headset to play with VR. Trying to determine which of the three would give the best experience got me curious in general about how much of a factor screen size plays in the experience. For example, all three phones have the same resolution, but they each have a different size screen - from what I have seen online, people say that the smaller screen will have a higher pixel density, thus a better image. Which leads me to my question: while it does make sense that higher pixel density would look better, in what other ways would the image look different (in the headset) compared to the larger screen? Ultimately, a larger screen will have a larger area devoted to the same piece of the image, so, it would take up more of your field of vision - thus, would you see more of the scene on the smaller screen than the larger screen? Would this effect quality? Does ppi strongly determine quality at the resolution of these phones? I'll admit, since this is going to be an almost $1000 purchase, I would like to get the highest quality experience; but, not being able to find a great deal of quality information, I'm, now, curious in general about what factors contribute to quality, and in what way.

To continue on this topic, I bought a very cheap $20 headset at Walmart and played around with my friends Note 8 for about an hour; would the more expensive Gear Headset have provided a better quality experience? In short, what does the headset contribute? How does it effect quality? Apologies if these are vague questions, most of the information I can find is just enthusiasts not saying anything technically clear or reviews of the devices as phones or spec sheets - I'd like to get a better understanding of the what's, how's, and why's of the different factors.

General interest aside, I have two (additional) questions that would help with my actual purchasing (if anyone is inclined to chip in on that note). I read online that the Note 8 doesn't default to its maximum 1440 resolution, but instead 1080 - I highly doubt that my friend adjusted this, so would the VR video player I installed have used 1080 or 1440 for the display? I ask since I wasn't that overly impressed with some of what I watched, but I'm not sure if this is because of the headset, because it just isn't that developed yet to give good results, or because the display was forcing a lower res than the video. And: supposing the smaller screened S8 (or S8+) would give a better experience because of higher ppi, would it be worth it over the Note 8, despite that the Note has an extra 2Gb of ram (in short, would the extra ram give a smoother experience and ensure there is less/no lag or stutter when running more intensive vr apps or videos)?

A final curiosity: Does a 360 VR video have lower quality than a 180 VR video? In other words, does the resolution of the video mean over some set angular area or over the whole video? Since if it is over the whole video, the area behind your head would be using some of the pixels that a 180 version could devote to the front - is that accurate? I ask since I watched a handful of videos and did notice some differences in quality, despite all of them having the same listed resolution; I'm not sure which were which, since I didn't have a lot of time to test, but I came up with this hypothesis when I was driving home, I was curious if it was correct.

I know there are a lot of questions here, I'm really just looking for any information beyond the vague accounts gotten from forums posts; thank you for reading:-) — Preceding unsigned comment added by 24.3.61.185 (talk) 10:44, 27 December 2017 (UTC)

😂

How does one type 😂 without copy/pasting it from somewhere? When I'm sending a Facebook message, I can type 🙂 by simply doing :-) and the messenger converts it to 🙂. However, I don't know how to type 😂 and don't expect to (I just encountered it a few minutes ago for the first time), and it seems like it would require a rather complex emoticon. Maybe it's a smartphone thing (I have a Samsung SPH-M400; no article); do smartphones have a Chinese-characters-like thing where you supply a name and it gives you a list of related emojis? Nyttend (talk) 22:58, 27 December 2017 (UTC)

That's U+1f602. How you'd enter it depends on your OS' Unicode input method. On Linux, I did Ctrl+⇧ Shift+u, release, 1f602↵ Enter -- Finlay McWalter··–·Talk 23:09, 27 December 2017 (UTC)

Of course, in practice, real people don't memorise pages of obscure unicode codepoints for weird icons they almost never use. Either you are stuck with cut and pasting it from somewhere, or your device has a menu which lets you browse through lists of such things. -- Finlay McWalter··–·Talk 22:28, 28 December 2017 (UTC)

On Windows 10 you can enable the onscreen keyboard, which lets you input any emoji you want by clicking on it -- 83.142.58.162 (talk) 14:46, 29 December 2017 (UTC)

Related, Category:Samsung mobile phones has almost 300 articles, including SPH M100, M300, M310, M520, and M620. Where would I find references for an M400? A quick Google search found lots of informal sites like the one I linked above, but I couldn't find anything to support an article; it would be nice to have an article (I could supply a picture) if someone knew where to find the sources. Nyttend (talk) 23:00, 27 December 2017 (UTC)

https://www.cnet.com/products/samsung-m400-sprint/preview/

https://www.pcmag.com/article2/0,2817,2412938,00.asp

https://www.samsung.com/us/support/owners/product/m400-sprint

(((The Quixotic Potato))) (talk) 06:59, 28 December 2017 (UTC)

@Nyttend: see above. (((The Quixotic Potato))) (talk) 19:48, 29 December 2017 (UTC)

@Nyttend: Try using emoticons :'‑) or :') (based on Wikipedia's article List of emoticons). --CiaPan (talk) 21:56, 29 December 2017 (UTC)

December 28

I have 2 questions about 2 different websites

1. Why is the Box office and Business button on the imdb's website on movie pages anymore? I would like to see a movie's filming dates? 2. Is this website in this link a reliable website where I can buy Xena merchandise because I emailed the person on link and it the mail address didn't work: http://www.alaska.net/~rlw/warriorhome.htm 50.68.252.153 (talk) 05:38, 28 December 2017 (UTC)

Regarding the IMDB, the buttons on their web site are their business. We don't know what they were thinking when they decided to have them. Filming dates are not something they routinely provide and I don't know any source for this information elsewhere. --76.69.117.217 (talk) 05:51, 28 December 2017 (UTC)

The link to this person's eBay auctions is also dead. I'd look somewhere else.OldTimeNESter (talk) 17:56, 28 December 2017 (UTC)

Problems with Windows 10

The other day I looked at the article Criticism of Windows 10 to see whether other people have the problems that I am having, and found none of them. So I made a list of them on the talk page, asking whether anybody can give references for these things so we can put them in the article (see my list). My talk page entry was immediately deleted by a certain person on the grounds that I was using the talk page as a forum. I protested that she didn't have the right to do that, and in the end took it to the Administrators' noticeboard. Someone there (see Wikipedia:Administrators' noticeboard/IncidentArchive972#Removal of a request on the Talk page of Criticism of Windows 10 suggested I bring up my request here. I'm not sure it's appropriate here, but I'm following his advice. Please Ping me if you answer! Eric Kvaalen (talk) 07:53, 28 December 2017 (UTC)

Hi.

You are in the right place.

However, correctly asking your question is an art. First, you should copy and paste your list here. Having people hunt for it reduces your chance of a getting reply. Second, you should filter out non-question items. For example, the following is not a question: "Windows 10 came with a Mail app that is a disaster. I won't bother saying what's wrong with it because of course you don't have to use it. I managed to get Windows Live Mail to work instead." Third, you should avoid linking to drama, such as ANI. It makes people dismiss your question as something with ulterior motivations.

Finally, you are in the weakest of the right places. As I told you, asking it in Microsoft Answers, TechNet Forum or Superuser.com is much more helpful. However, judging by your list, you are in serious need of technical support. That, and a good book about Windows 10 and its features. You could use some familiarity with new features of the operating system.

Best regards,
Codename Lisa (talk) 10:28, 28 December 2017 (UTC)

It turns out there are people like me in this Universe. I opened up this Computer Desk with a resolution to complain about Microsoft and Windows 10. This is one of them. I have Google browser on my desktop. I prefer Google. I click on the icon and Google browser shows up. I enter a web address in the top narrow window and click CR. I get a white screen with a few sentences. I give you an example when I tried to open The Wall Street Journal front page[1]. This is what I see.

• Hmmm...can’t reach this page
• Try this
• Make sure you’ve got the right web address: https://www.wsj.com
• Search for "https://www.wsj.com" on Bing
• Refresh the page

Of course it is a lie. IT IS A LIE. I click on this link now and get a bunch of various ads and links which I better avoid using, but the "https://www.wsj.com" is one of them and finally I get my newspaper after jumping through some hoops. Why does Microsoft do it? Because they make money on their own advertisement on Bing but not when the ads appear in Google. Is it a result of the fact that the Internet Fairness act has been repealed?

The problem when the whole computer freezes with overload by advertisements is simply an icing on this rotten cake. AboutFace 22 (talk) 21:02, 28 December 2017 (UTC)

This isn't the right place to complain about anything. The closes I can see in what you say would be to rephrase as why does your computer freeze when you do xyz. Dmcq (talk) 19:18, 29 December 2017 (UTC)

The problem is in your computer, not in Win10. First, 2Gb is quite low for Windows 10. I recommend 4 GB minimum. Second, your hard drive may be not in good shape. You should check it for errors. Third, you may have some malware installed. You should check your computer using an antivirus software. Ruslik_Zero 19:31, 29 December 2017 (UTC)

I find that 4GB is quite small - in my experience, it spends a lot of time swapping memory to HD with only 4GB. I would certainly go beyond 4GB. At least add 4GB to get to 6GB and at least 8GB will be better. Personally, I have a minimum of 16GB, but that is me. Bubba73 ^{You talkin' to me?} 01:42, 30 December 2017 (UTC)

Do you have Defragmenter turned off? Have you defragmented recently? Fragmented files can significantly increase launch times and file retrieval time from the hard disk. To check your setting and run the defragmenter: Click Start button; scroll to Windows Administrative Tools and click it; click Defragment and Optimize Drives. My experience is that every time Win10 downloads and installs a really big update, as it did recently, Defragmenter must be run very soon after, apparently because many existing files are moved in fragmented fashion so that the update files can be installed unfragmented. Akld guy (talk) 00:46, 30 December 2017 (UTC)

@Eric Kvaalen: Pinging as you requested to ensure you don't miss the replies! You should better hope mw:Extension:StructuredDiscussions to be adopted on pages like this when it leaves beta and gets deployed in enwiki. It takes care of notifying users, you see! :) - - Kaartic ^{correct me, if i'm wrong} 12:49, 30 December 2017 (UTC)

@Akld guy, if your suggestion about defragmenting was aimed at me, then NO, my disks are all 0% fragmented. AboutFace 22 (talk) 16:26, 30 December 2017 (UTC)

This is Eric again. I will answer here to all the above. First of all (to Codename Lisa) the person who advised me to put my question here said I should make it much shorter. So I just put a link to my list instead of listing all the problems again. And my question was not "How can I solve these probllems", (though I wouldn't mind someone telling me if he or she knows how to solve one or more of these problems), my question was do other people have these problems and if so what can we use as sources to modify the Criticism of Windows 10 article! I think it's really bad on the part of Microsoft to give us such a rotten Mail app with Windows 10. It would do things like committing suicide (disappearing from my tasks) when I was in the middle of writing a letter! (I had closed my laptop to take a train, and when I woke it up that Mail app was closed and my letter had vanished.) I had used Windows Live Mail in the past, and they sent me an e-mail saying it would no longer work with Hotmail. Which after a year or two of suffering with the Windows 10 app I discovered was a lie – you just have to configure the mail server in Windows Live Mail a bit differently! Finally Lisa, the reason I linked to "ANI" was that I didn't think putting this question here was the right thing to do, so I was giving my excuse for doing it.

Oh, and Lisa, as to me being in serious need of technical support, I mentioned that I have had these problems from Day One. It's not due to viruses or something. (Maybe some of the problems are due to the McAfee that came with the computer, but only part of the problems.) And what do I need to study the new features for? I just want to use my laptop for Internet browsing, text processing, mail, and spreadsheets. As I would do decades ago with Windows 3 just fine.

Now, Ruslik0, I don't know whether you were writing for me or for AboutFace 22. I'm the one who has only 2 Gibibytes of RAM. I once had a computer with 4, but otherwise I've always had 2 or less. (Much less in the olden days!) And the versions of Windows I had then worked better. Bubba73, I don't see why I should have a lot of RAM when I'm not doing anything in particular. It's as though they've made Windows much less efficient. I'd be surprised if my hard drive has errors. As I have said, I've had these problems form the very beginning of using this computer. Same thing for malware. (Note added later: I've just tried checking my disk for errors and I immediately get a message that says "You don't need to scan this drive. We haven't found any errors on this drive. You can still scan this drive if you want.")

Akld guy, I never turned off any defragmenter. But of course a fragmented disk wouldn't be the explanation for why I had these problems when I first got this computer and put Windows 10 on it. My disk is mostly empty. Anyway, I've just checked the way you suggested, and it says my partitions are 0% or 1% fragmented, and "scheduled optimization" is "on", with frequency "weekly".

And Kaartic, thanks for Pinging me. No one else did.

Eric Kvaalen (talk) 20:32, 30 December 2017 (UTC)

Windows 10 will run with 2GB but even Microsoft recommends 4GB. You say that the old versions of Windows worked better. having more RAM will help a Windows 10 computer.

Here are two YouTube videos.

• video 1
• video 2

The first one compares 4, 8, and 16 GB. Sometimes extra RAM makes essentially no difference but sometimes it makes a huge difference. It recommends 8GB. The second video discusses it, but I haven't watched the whole thing. Bubba73 ^{You talkin' to me?} 21:14, 30 December 2017 (UTC)

The complaint list has indicators that RAM isn't the problem here. On similar hardware, Windows 10 is faster than Windows 7 (but slower than Windows 8); that's a fact. Furthermore, the complaint list mentions high CPU and disk I/O traffic. While the I/O traffic by System can be attributed to paging, high CPU usage and high disk I/O by other processes cannot be alleviated by more RAM.

In addition, the complaint list says the system sometimes comes to full halt; the Start menu does not open smoothly and File Explorer doesn't launch reasonably fast. And the context menu doesn't appear on command either. All of this point either software bloat or malware infection. Even on a system with the minimum hardware requirements, Windows responds smoothly. Finall, the Alt+Tab complaint is very suspicious; it either means something has hijacked it or Eric is running a very old version of Windows 10 (maybe a beta version).

Also, there are other things to consider: The user in question delays coming here; when he comes here, he is not actively watching the thread for an answer; he'd rather talk back than cooperate in solving the problem. Therefore, I am not ruling out that this whole hoopla is just for throwing mud at Windows 10. Mind you, I am not saying I am against it. I am saying Wikipedia is not a battleground.

Best regards,
Codename Lisa (talk) 09:50, 31 December 2017 (UTC)

@Bubba73: Thanks. The first video concludes, "If you're using your computer just for gaming, 8GB is the best option. Hoever, if you're doing a lot of video editing, converting, file compressing and such, you should definitely get 16 GB RAM." Well, I don't do any of that! The second one is about whether 8 or 16 is needed for gaming. Well, I don't play games either. So I didn't bother to listen to the other 19 minutes.

@Codename Lisa: I'm glad to see someone (you) agrees with me that low RAM can't explain many of my problems. See Talk:Criticism of Windows 10 where someone else suggested that, and my reply. I was using Windows 7 with 2G of RAM from 2011 to 2014, and did not have the kinds of problems I'm having now.

I don't see how I can have software bloat or malware infection. I have only installed a few things like Firefox, VLC, and LibreOffice, and these problems started immediately when I installed Windows 10 on this new (at the time) computer. It had McAfee preinstalled as well (free for a couple months I think).

I am not running an "old version of Windows 10"! I get all the updates.

I did ask people to Ping me when they answered, and no one did except one guy who was nice enough to Ping me even though he didn't have anything to add to the discussion! I do have a life, other than arguing about Windows 10 after all. I admit that I didn't come here to solve my computer problems. I came here on the recommendation of someone at the Administrators' noticeboard in order to pursue my question of whether other people have these problems, and if so do we have some references.

Eric Kvaalen (talk) 12:53, 1 January 2018 (UTC)

Hello again.

You wrote: "I don't see how I can have software bloat". Well, you said it yourself. Earlier, you wrote: "I've noticed using the Task Manager that it loads all kinds of things that I never use". What you are describing in this sentence is called "software bloat", i.e. unwanted software being on your system.

Alright, let's see if I can help you.

First thing, first: Please tell us the full version number of your Windows 10. To get it, open the Run... dialog box (⊞ Win+R) and issue a winver command. The first top two lines of black text should read like this:

Microsoft Windows
Version 1703 (OS Build 15063.786)

In your case the second line may say something different. That's the info that I need.

Second, please open Task Manager, go to the Startup tab, disable everything you see there, and restart your system. Then, tell us the result. Maybe you lose functionality; maybe not. Also, the name of the make and model of your laptop would help lot.

Best regards,
Codename Lisa (talk) 14:07, 1 January 2018 (UTC)

@Codename Lisa: See lower down. Eric Kvaalen (talk) 15:59, 3 January 2018 (UTC)

Nevertheless, Windows runs better with 4GB than it does with 2GB and better with 8GB than with 4GB. Memory sticks of 2GB are so small that they are useless to me. I give them away. I'd send you some for free if I still had some. Bubba73 ^{You talkin' to me?} 16:38, 1 January 2018 (UTC)

One thing - if you have the 32-bit version, 4GB is the maximum. Bubba73 ^{You talkin' to me?} 19:22, 1 January 2018 (UTC)

Thanks, Bubba73 and Lisa. Bubba, my computer is 64-bit. (Which I think is the reason I can't run a lot of old programs...)

Lisa, I just restarted my computer because it was behaving real bad, so now it's all right. The things in Startup of Task Manager are:

1. OneDrive
2. Realtek HD Audio Manager
3. Skype
4. SpotifyWebHelper
5. SrvMod
6. Windows Defender notification icon

I'm sure I can get rid of OneDrive, but I think I would rather have Skype start up, and the others I don't know whether they're needed or not. I have no idea what they do.

Anyway, the version number which you asked for is 1709 (OS Build 16299.125). Why do different people have different versions if the updates are automatic?

When you said software bloat, I thought you meant that I had installed too much stuff. If you're talking about stuff that Windows 10 gives me by default, then that's what I call a legitimate thing to criticize.

Eric Kvaalen (talk) 17:29, 3 January 2018 (UTC)

Regarding IMDB

Is there a way I can contact the people who run the IMDB? 50.68.252.153 (talk) 09:22, 28 December 2017 (UTC)

Have you tried http://www.imdb.com/helpdesk/contact ? --Phil Holmes (talk) 10:11, 28 December 2017 (UTC)

In Wikia, searching all pages that are in two categories

In a Wikia website like http://disney.wikia.com/ , is there any way to search all pages that are simultaneously in two categories? --Daniel Carrero (talk) 22:14, 28 December 2017 (UTC)

Search for a random string that doesn't have a result. Click on the Advanced link to the right-hand side of the page. In the revealed area, click the Sections you wish to search in. LongHairedFop (talk) 14:14, 29 December 2017 (UTC)

December 30

LED screens for portable electronic devices that are not OLED

Could screens for portable devices be composed of a array of really small LEDs (but without organic components like OLED)? That is, not back illuminated by LED, but each pixel consisting of a micro LED. I only know LED screen in outdoor displays.--Hofhof (talk) 01:29, 30 December 2017 (UTC)

Yes. The problem is that the smallest LEDs are far too large to make a display that anyone would want to use. Instead, you'd have to create a sheet of LED-like molecules that you can independently ionize to create light. In other words, you'd just be reinventing the OLED display. 71.85.51.150 (talk) 03:24, 30 December 2017 (UTC)

They are working on that right now Fëanor Engineering (talk) 11:10, 30 December 2017 (UTC)

GUI ambiguity

I've been using google hangouts recently. This has a button marked "mute" (with a picture of a microphone with a line through it). But I never know whether this means "press this button to mute your mic", or "your mic is now muted, press this button to unmute". I see this very annoying ambiguity very frequently, in many contexts (not just sound). Is there a name for it? Robinh (talk) 02:00, 30 December 2017 (UTC)

Apparently the problem is not just you: [2].

Does the button change color/form/sign when you press it? Does it display any text?--Hofhof (talk) 02:52, 30 December 2017 (UTC)

Heh, good to know it's not just me. But the problem is universal: for example on my ubuntu box, for bluetooth, there is a toggle switch with two settings: "on" or "off". Does "on" mean "bluetooth is currently on, press this button to turn it off", or does it mean "bluetooth is currently off, press this button to turn it on"? Or is this obvious to most people? Robinh (talk) 03:54, 30 December 2017 (UTC)

The controls are called "flip-flop buttons" in Alan Cooper's book About Face: The Essentials of User Interface Design.[3] The problem itself is common, but I don't know if it has a specific name. Mitch Ames (talk) 13:34, 30 December 2017 (UTC)

(OP) Thanks for this Mitch. The stackoverflow page is great: very nearly all the posters understand the problem, and most despair of unthinking and confusing UI design. As far as actual usage is concerned, it seems that in about half of interfaces, "on" refers to the state and in rest "on" refers to the action. Robinh (talk) 18:50, 30 December 2017 (UTC)

Privacy violation (or) Missing Terms of Service - what action to be taken?

On my birthday (that happened a month ago), I received an SMS to my "personal" mobile number from a travels related website. The message wished me a happy birthday (specifying my age) while giving me an offer of 10%. This shocked me more than it surprised me for the following reasons,

1. I have no idea about that website up and until I got that message
2. I don't disclose my personal mobile number or my birthday unnecessarily. The fact that they got my Name, DOB, Phone number correctly was a great shock!

I tried to narrow down the potential services that I use which might have gave my personal information to that website. I was able to narrow it down to one service. It's a service I use to book train tickets in my country (India). I was even more shocked when I came to know that I was using a service which neither had a "Privacy Policy" nor a "Terms of Service" !

I even pinged them about the lack of Privacy Policy a month ago but no reply (except for the automated reply) until now. I'm pretty sure that they would be the one who would have given out my information without my consent. I would like to take action against them. Further even if the service isn't behind the SMS I got on my birthday, I would like to take action against them for not having a Privacy Policy or ToS. I'm not sure how to go about it. Any guidance as to what I could do about this "privacy information leak without permission" or "missing Terms of Service" issue would be helpful.

Note: If this isn't the right place to ask, please point me to the right locations if possible. - - Kaartic ^{correct me, if i'm wrong} 18:18, 30 December 2017 (UTC)

I am not sure why you are asking here? This is a "computer desk" intended for question related to computers. Ruslik_Zero 20:13, 30 December 2017 (UTC)

You are not why answering Good English Ruslik. The "computer desk" not intended ungrammatical criticism. μηδείς (talk) 20:33, 30 December 2017 (UTC)

@Kaartic: You can try [this consumer protection link] which deals with unsolicited SMS communications and is linked to by the Telecom Regulatory Authority of India's main website. You can also call your phone service provider and ask for a number for regulatory complaints/inquiries regarding uninvited solicitations or talk to a lawyer. μηδείς (talk) 20:33, 30 December 2017 (UTC)

December 31

C programming — how do I view the 8, 32, or 64 bits of binary information at a known memory address?

• "Main memory or RAM is arranged as an array of "sets of electronic on/off switches" or locations beginning at address 0. Each location can store usually 8, 16, 32 or 64 bits."
• "Memory can be thought of as an array of bytes where each address is one index in the array and holds 1 byte."
• My final attempt of getting help before coming here to the ref desk! Ԅ

I'm an absolute beginner. I just joined codeacademy last month and more recently I've enrolled in Edx's premiere computer science class CS50! I just learned through wikipedia how to find the memory addresses of any data type just by typing "%p, &shark inside the printf function and now I'm like a giraffe who discovered the stepladder!

Is there a clean, fool-proof way for me view the 8, 16, 32, or 64 bits of ANY memory location just by having that memory location's address? (e.g. 0x7ffed73897d8) In other words—if I know the address—is there a program or line of code which can "print for me the 8, 16, 32, or 64 bits of binary information" at the known address? 67.233.34.199 (talk) 03:03, 31 December 2017 (UTC)

Here's the thing: all data in any typical computer is binary. Any time you're printing output, you are "printing binary information". Your code just usually tells the computer to interpret said data in a particular way, such as an integer value within a certain range. This is a thing a lot of beginning programmers have trouble wrapping their heads around. Computers are dumb. They don't know what a "number" is. They just process data according to the instructions they're given. If you tell the computer to interpret a value as a 32-bit signed integer, it will do that. If you tell it to interpret it as a name in a database, or a pixel in an image, it will do that. Now a second thing: on most modern computers, you can't arbitrarily access memory addresses in a program. The reasons take a while to explain in detail, but they have to do with virtual memory and operating system access controls. You usually can view a process's memory contents with a debugger, and sometimes other ways as well, like through the proc filesystem on Linux. (Sometimes this requires administrator privileges.) If you do want to play around in an environment where you can access arbitrary memory, try an emulator for a platform without memory protection, such as Dosbox.

Anyway, to sort of answer your question, C gives you types for accessing fixed bit-width values, instdint.h. Note this requires C99, but if you're trying to learn in an environment without C99 support, throw it out and use one that does. Note you will see a lot of stuff online telling you to do things like use a char* to read a single byte. This is wrong in plain C because the size of types like char is platform-dependent. Using char as a synonym for "8-bit byte" was common in pre-standard C, and old habits die hard. With that said, POSIX does mandate char be exactly eight bits, so if you're writing explicitly for POSIX platforms you can assume that. Here's an example for looking at a 32-bit chunk of memory. As I said, on modern platforms you can't access arbitrary memory addresses, so instead we're just going with whatever the operating system gives us off the heap with malloc.

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
int main() {
	uint32_t *ptr = malloc(sizeof(uint32_t));
	if(!ptr){return 1;}
	printf("Value: 0x%x Address:0x%x\n", *ptr, ptr);
	free(ptr);
}

This prints the value and address pointed to in hexadecimal. C has no built-in support for printing values in binary because it's rarely useful; hexadecimal is what programmers usually use for displaying "raw" data. As a teaching exercise, you can try using this macro for binary output. For pedagogical value, I've done things right by checking for malloc failure, and freeing the malloced memory after using it. Obviously this isn't necessary in a toy program, but in "real" programming you should always do these. Note as well that forgetting to assign something to a malloced pointer is a common mistake. Here it isn't a mistake because we want to see whatever's in the memory location already. It's possible that you might always get a value of 0, because these days it's increasingly common for systems to zero out memory when it's allocated by a process. --47.157.122.192 (talk) 10:48, 31 December 2017 (UTC)

Oh, and here's a fairly good Wikibooks page on stdint.h. --47.157.122.192 (talk) 11:24, 31 December 2017 (UTC)

In addition to the reliable types defined in stdint, inttypes.h defines reliable printf format specifiers for the same specific sizes. So:

#include <stdio.h>
#include <inttypes.h>
#include <stdint.h>

void print_values(uint64_t* p){
  printf ("values at %p:\n", p);
  printf (" 8 bit:  %02"   PRIx8  "\n", (uint8_t)*p);
  printf (" 16 bit: %04"   PRIx16 "\n", (uint16_t)*p);
  printf (" 32 bit: %08"   PRIx32 "\n", (uint32_t)*p);
  printf (" 64 bit: %016"  PRIx64 "\n", (uint64_t)*p);
}

int main () {
  const char test_data[] = { 0x12, 0x34, 0x56, 0x78,
                             0xf1, 0xe2, 0xd3, 0xe4 };

  print_values((uint64_t*)test_data);

  return 0;
}

-- Finlay McWalter··–·Talk 11:09, 31 December 2017 (UTC)

In fairness I should note that inttypes.h is a C99 feature, and MSVC's support for C99 has been patchy. It seems they added support for this in the 2013 version (but I've not personally tested this on that platform). -- Finlay McWalter··–·Talk 14:59, 31 December 2017 (UTC)

Yes, that's the right way to do it. For some reason I was thinking printf did some magic with the width of its arguments. Moral of the story: 1 AM is not the best time to program. --47.157.122.192 (talk) 21:37, 31 December 2017 (UTC)

I think the bigger problem here is that, given memory protection, memory virtualization, address randomization and other such things, there may not even be an address "0x7ffed73897d8" from which you can read. If you absolutely, positively need to read from an address given as a literal, you cast that literal into a desired pointer type and use the pointer to obtain the value stored at that address (i.e. dereference it), like this:

printf("%d\n",*(int*)0x7ffed73897d8);

This is it, as far as C is concerned, but see above. Your program will most likely crash. In simpler systems running on simpler hardware, such as DOS running in real mode, this was, however, a totally "legit" way to access memory at known addresses, for example in order to write to the video memory or to read the BIOS data area that contained various useful info about the computer (such as the number of floppy drives or COM ports and their respective addresses.) 78.50.124.31 (talk) 20:38, 31 December 2017 (UTC)

I take it your misconception about memory stems from the phrasing "can be thought of as an array... at location 0." This is a simplification, but good for you thinking ahead, apparently you're the first participant of your course to do so 78.50.124.31 (talk) 20:59, 31 December 2017 (UTC)

C programming — "printf("%d\n",*(int*)0x7ffed73897d8)" worked and I'm elated!

I'm happier than a clam at high tide! Now I have a whole host of experiments I'm wishing to do because I want to test and verify for myself a lot of questions along the lines of "what will happen if I do x" and I needed to know this particular line of code. The other solutions worked when I ran them in codeblocks (although not in the cloud ide that CS50 uses) but I didn't fully understand what I was seeing nor how to tinker & substitute my own memory addresses into the code, which is fine for now.

The other great thing I really like about computer programming is the absolute freedom you have to write and instruct the computer to do anything you want — no questioning, no second-guessing, no backtalk — especially if you are the type of person who gets joy at telling the computer to perform purposeless tasks. Thanks again, everyone! 67.233.34.199 (talk) 11:57, 1 January 2018 (UTC)

Who or what can fix corrupted and unplayable video files?

I don’t know if this is an appropriate place to post this or if I should frame the question differently. I’m going to go ahead and explain and ask. I recently went on a trip where I took a lot of videos. I have a USB drive that you can put in to an iPhone on one end and the computer on the other end. To free up some space on my iPhone to continue recording, I moved some of the video clips directly to the USB drive. However, when I returned home and started going over the videos I put in my USB drive, my computer and my iPhone were unable play the videos except for the first few. 9 of the videos won’t even copy and paste to my computer. Is such an issue fixable? Who are what would be able to fix corrupted/unplayable videos? Willminator (talk) 03:22, 31 December 2017 (UTC)

Did you check the file system on your USB drive for for errors? Ruslik_Zero 16:41, 31 December 2017 (UTC)

I don’t know. Are such files recoverable? Willminator (talk) 21:27, 1 January 2018 (UTC)

Is the USB drive a brand name drive purchased from a reputable seller or a generic drive bought online at a seemingly bargain price? The reason I ask is that there is a long running scam involving both USB flash drives and SD cards where low capacity drives and cards are hacked and relabeled so that they appear to have a much higher but false capacity. (Briefly discussed in USB flash drive.) Products with only a few GB of real memory can be modified to show as much as 2TB of false capacity. Data may appear to write successfully to such drives (or cards), but past some point, the data is irretrievably corrupt when read back. -- Tom N talk/contrib 04:27, 2 January 2018 (UTC)

Can these scam drives be modified to correctly report the true memory capacity? Graeme Bartlett (talk) 05:32, 3 January 2018 (UTC)

In theory, the Flash memory controller firmware can be restored to its original state by overwriting the hackers' Custom firmware with a copy of the genuine control program, but this is a specialist task and probably requires detailed knowledge and specialist equipment. I wouldn't know where to start. Restoring the original control ware would not recover data that has already been overwritten, but it would prevent overwriting in future. It's probable that only a few bytes have been changed, just allowing the control program (hidden on the USB drive) to re-use memory locations that should have been protected because they already contain valid data. If the USB drive was genuine, and files have not been overwritten, then sofware is available to recover files from a damaged file structure. I have some that works well for pictures, but maybe not for videos. Dbfirs 16:21, 3 January 2018 (UTC)

iPhone and Android smartphone

Apple's iPhone don't have memory card slot. It's RAM is not more than 1gb (5 or 4 model). It's screen size is smaller than Android phones. Inspite of all these factors people buy it at awesome prices! (Which are far far higher than Androids having all I have just mentioned).Why is that? No, it can't be just brand mania. Or is it?  Jon Ascton  (talk) 07:02, 31 December 2017 (UTC)

One assumes people buy it because they like it better than competing products. As for why, you'd have to ask them. Please note the page header, which states that we don't accept requests for opinions, predictions, or debate. I will note that at least in the U.S., iPhones and top-end Android smartphones are priced comparably. For instance, the iPhone 8 Plus MSRP is $799, while that of the Samsung Galaxy S8+ is $824.99. --47.157.122.192 (talk) 11:00, 31 December 2017 (UTC)

Neither 5 nor 4 models are sold now. Ruslik_Zero 16:46, 31 December 2017 (UTC)

Apple already had a giant "start" into "mobile electronic" with the iPod, which, like the iphone, was "first" of its category and also "best of art" for long enough to become famous and iconic. Of course its brand mania to some and a divine altar to others. I never understood why everyone wanted a Mercedes Benz - even Janis Joplin [4]. I always only wanted a Porsche. --Kharon (talk) 17:44, 1 January 2018 (UTC)

You should consider Geländewagen. Ruslik_Zero 19:13, 1 January 2018 (UTC)

Nah, i live in Berlin and we have Carsharing here. They have neither Porsche's nor Mercedes'es* but atleast i have a Samsung S7 android phone now. *(Oh, i forgot they do have Mercedes trucks :).--Kharon (talk) 04:55, 3 January 2018 (UTC)

Hardware specs are not all that people are interested in, and opinions on what is good differ. I like my iPhone 5s because it is quite small, not despite of it. If I need a big display, I have a 27" monitor. I've never suffered from RAM shortage on the phone, and despite being a computer nerd, I don't even know how much RAM my phone has - it's as with the question about horsepowers of a Rolls Royce: the answer is "enough". Typical advantages of iPhones are excellent integration with other Apple products, long product support (including software updates - the 5s was released in 2013 and still runs the latest iOS), a clean and simple product line-up, and, usually, top CPU power and top or near-top cameras for their generation. Some Android phones have some advantages over iPhones, but, as mentioned above, the ones that come close in most aspects also come close in price. --Stephan Schulz (talk) 16:26, 2 January 2018 (UTC)

January 2

Ubuntu 16.04 with Nemo

Hi. I've been having trouble getting some of my thumbnails to show on Ubuntu 16.04 and i'm out of options as to what is causing it. I edit my music files to have covers and change the icons. When i do this only 1 image icon changes (instead of all 12). I increased the thumbnail setting up to 8GB and installed Gedit to push it to maximum. Now the icons display perfect on thumb drives connected to Ubuntu or Windows, but not when copied to Ubuntu desktop. Does anyone know how i fix this? I'm using Nemo, instead of Nautilus. Thanks 81.137.240.118 (talk) 10:48, 2 January 2018 (UTC)

Database software

I'm currently using "MS Excel v2010" for databasing purpose. What else would you recommend?

Note: I've used "MS Access v2010" in the past. I have to learn it again if you direct me to it. What I recall, you can attach or link image files in it, just like "MS Excel v2010". Am I right? Plus, a tutorial is sought if you guide me to this please.

123.108.246.90 (talk) 15:34, 2 January 2018 (UTC)

We can't recommend anything without knowing what you want it for and why Excel doesn't meet your needs. I suggest you take a look at Comparison of object database management systems, Comparison of object-relational database management systems, and Comparison of relational database management systems.--Shantavira|^{feed me} 16:10, 2 January 2018 (UTC)

You won't be able to link images (or anything else) in Access, at least not that I'm aware (and I was an Access programmer for several years). You can link to an existing Access database in an Excel spreadsheet, however, through either a Data Link, or ODBC. As to whether to use Access or Excel, if you really need a database, then I would recommend taking the time to re-learn access. You can duplicate much of what a database does in Excel using spreadsheet links and the various LOOKUP functions, but this becomes unmanageable very quickly (trust me, I've seen it). Access is pretty easy to learn, especially if you've used it before, and Microsoft has several video tutorials online (which is how I first learned to work with it).OldTimeNESter (talk) 02:46, 3 January 2018 (UTC)

https://support.office.com/en-us/article/access-video-training-a5ffb1ef-4cc4-4d79-a862-e2dda6ef38e6 (((The Quixotic Potato))) (talk) 15:00, 3 January 2018 (UTC)